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What Does the AFUE Rating on a Furnace Mean for My Heating?

The energy efficiency of the furnace that keeps your house warm is one of the most important things to know about it. You can use it to estimate how much a furnace will cost to run, and it also serves as an early warning of repair issues should the furnace start to create higher heating bills than normal.

Central furnaces, whether gas or electric, have their efficiency measured in AFUE, an acronym for “Annual Fuel Utilization Efficiency.” Understanding how AFUE is measured will help you better understand your furnace. It will also caution you about when to call for repairs or schedule a replacement for the furnace. When you need expert service for your furnace, call on a highly-trained team with a long history in the HVAC industry in Fresno with heating: Purl’s Sheet Metal & Air Conditioning.

What the AFUE Rating Means

Annual Fuel Utilization Efficiency is expressed as a percentage. This percentage is the amount of energy put into the furnace that it converts into heating power, as measured over a year. The larger the percentage, the more fuel is turned into heat and the less is wasted as exhaust. For example, if a gas furnace produces on average 90 BTUs for each 100 units of natural gas that it burns, then it has an AFUE of 90%.

The Federal Trade Commission requires that manufacturers of furnaces include AFUE ratings on all new units. A non-condensing furnace must have a minimum of 78% AFUE (unless designed for a mobile home). The Department of Energy has new requirements for furnaces that are set to go into effect on January 1, 2015: all weatherized gas furnaces must have 81% AFUE after this date.

However, many furnaces score much higher AFUE ratings than this. High-efficiency furnaces often rank above 90% AFUE. Electrical furnaces are also extremely fuel efficient, but electricity is usually a more costly energy source. If you are planning to have a new furnace installed, you will need assistance from heating and cooling experts to find the right balance of efficiency and cost to fit your home and budget.

As long as your furnace receives regular annual maintenance from skilled technicians, it should keep 95% of its efficiency for most of its service life. If you notice a spike in your heating bills, it can mean your furnace needs repairs or it has reached a point where it is losing efficiency due to age. In either case, call for furnace professionals to look into the issue and see what needs to be done.

Purl’s Sheet Metal & Air Conditioning has many decades with residential furnaces in Fresno. Whether you need new installation, maintenance, or repairs to protect your home’s heating, you can count on our services seven days a week.

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